See you in Istanbul. It is expected to be a big event, with thousands of attendees.

In the session the speaker explains the concepts of smart contracts and DApps and demonstrates how to build, deploy and run a simple decentralized app in the Ethereum blockchain network, using a Solidity smart contract, with a JavaScript-based front-end, interacting with the contract through the MetaMask in-browser wallet and the Ethereum Web3 API.

The DApp is called “Document Registry” and is simple: it holds a set of documents and can confirm the existence of certain document (e.g. course certificate, diploma of graduation or loan contract) at certain date in the past. The DApp uses the decentralized storage system IPFS to hold the document contents and keeps their hashes on the blockchain (in the Ropsten Testnet for the demo).